The overall objective of this proposal is to improve therapeutic outcomes for children with primary brain tumors. This will be accomplished by Phase I and II clinical evaluations of promising new therapeutic drugs, delivery technologies, biological therapies, and radiation treatment strategies conducted by a newly-established Pediatric Brain Tumor Clinical Trials Consortium (PBTC). This consortium will combine the experience and resources of eight outstanding medical institutions in an organizational structure designed to facilitate a rapid and successful study of new therapies for childhood brain tumors. A second objective is to utilize the consortium mechanism to share brain tumor specimens as well as other clinical and laboratory data and to conduct research pertaining to neuroimaging, pharmacology, and the biology of childhood brain tumors. To achieve these objectives, the PBTC must rely on the special strengths and resources of each participating institution. Accordingly, we propose the following Specific Aims to advance PBTC goals: Aim 1. to participate as a Member Institution in PBTC clinical trials, laboratory, and neuroimaging studies; Aim 2. to develop new experimental therapies for CNS tumors in children and propose these strategies for phase I/II clinical trials by the PTBC; Aim 3. to propose and facilitate the development and study of intrathecal therapies for the prophylaxis or treatment of childhood CNS tumors; and Aim 4. to propose and develop neuroimaging studies of regional tumor pharmacokinetics and brain tumor biology for participation by PBTC members. The Children's Hospital of Philadelphia (CHOP) has: (1) an outstanding multi- disciplinary clinical team of internationally-recognized leaders in pediatric neuro-oncology, radiation oncology, neurosurgery, neuro-radiology, pharmacology, and new drug development; (2) a large number of patients with childhood primary brain tumors available for study; (3) state-of-the-art facilities for diagnostic and research neuroimaging (MRI, MRSpectroscopy, PET, SPECT), neurosurgery (computer image-guided surgery), and radiation therapy (stereotaxic radiosurgery, Gamma Knife, brachytherapy); (4) an NIH-funded brain tumor bank which stores brain tumor biopsies from CHOP, NYU, and Beth Israel (NYC) (5) internationally-recognized expertise in neuro-pathology; (6) extensive institutional resources for biostatistics and clinical trial data management and a reputation for excellence in clinical care and research; (7) experience in the organization and coordination of multi-institutional clinical trials; and (8) a large number of high quality, clinically relevant, peer reviewed and NIH funded brain tumor research studies. These programmatic and institutional strengths support the feasibility of our specific aims, are responsive to the criteria for consortium participation specified by the RFA, and substantially enhance the likelihood that the PBTC will achieve its long-term goals.